Timeline for products and smooth/étale/unramified morphisms
Current License: CC BY-SA 2.5
9 events
| when toggle format | what | by | license | comment | |
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| Apr 24, 2010 at 2:31 | history | edited | Emerton | CC BY-SA 2.5 |
added 17 characters in body
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| Feb 9, 2010 at 21:36 | comment | added | Qing Liu | Non, mais on n'a pas le droit de dire des gros mots :) | |
| Feb 9, 2010 at 21:22 | comment | added | Georges Elencwajg | Tiens,les djeunz disent encore scrogneugneu? (that's for Qing Liu) | |
| Feb 9, 2010 at 21:04 | comment | added | Qing Liu | Scrogneugneu (that's for me). Thanks Arne and Matt. The exercise is completely wrong as explains clearly Matt. If I remember well, originally I though about the case of two smooth curves Y, Z which are finite covers of a smooth curve X. Then $Y\times_X Z\to X$ is <b>ramified</b> at every point $(y,z)$ in the product such that one is étale and the other one is ramified. I don't know how this s.. heu, incorrect statement came. | |
| Feb 9, 2010 at 20:57 | comment | added | Wanderer | Yes, that's the point. | |
| Feb 9, 2010 at 20:34 | comment | added | Georges Elencwajg | So the exercise is false, or am I missing something? | |
| Feb 9, 2010 at 19:50 | vote | accept | Wanderer | ||
| Feb 9, 2010 at 19:48 | comment | added | Wanderer | Thanks. I wondered whether I was missing something; this is exercise 3.11 (page 145) of Liu's book, in which he asks to prove that the result is true - i.e. that $Y \times_X Z \to X$ is always smooth/étale/unramified. | |
| Feb 9, 2010 at 19:44 | history | answered | Emerton | CC BY-SA 2.5 |